Oil burner nozzle



Sept. 25, 1951 E, EARL 2,568,879

OIL BURNER NOZZLE Filed March 17, 1948 lb 46 41 f 43 22 4s l4 H INVENTOR.

HQWARD E. EARL Patented Sept. 25, 1951 OIL BURNER NOZZLE Howard E. Earl, Bloomington, Ill., assignor to Eureka Williams Corporation; Bloomington, Ill., a corporation of Michigan Application March 17, 1948, Serial No. 15,411

2 Claims.

This invention relates to nozzles adapted for use in forming a primary mixture in low-pressure type oil burners. The primary mixture so formed is burned in the combustion chamber of the oil burner with secondary air supplied to the combustion chamber around the primary mixture nozzle referred to.

An object of the invention is to provide a better and a more quiet and efficient nozzle for employment in the formation of a primary mixture in oil burners of the type referred to. Other and further objects of the invention will be apparent by reference to the accompanying drawings of which there is one sheet, which, by way of illustration, shows a preferred embodiment and the principles thereof and what I now consider to be the best mode in which I have contemplated applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art with-out departing from the present invention and the purview of the appended claims. I also contemplate that of the several different features of my invention, certain ones thereof may be advantageously employed in some applications separate and apart from the remainder of the features.

In the drawing:

Fig. 1 is a fragmentary cross sectional view of an oil burning furnace having a low-pressure type oil burner applied thereto, the oil burner referred to having a primary mixture nozzle embracing the principles of the present invention;

Fig. 2 is an enlarged fragmentary longitudinal sectional view through the primary mixture nozzle illustrated by Fig. 1;

Fig. 3 is a cross sectional view of the nozzle taken substantially in the plane of line v3-3 of Fig. 1; and

Fig. 4 is a cross sectional view of' the nozzle showing an end elevational view of the inner tubular body structure embraced therein. Fig. 4 is taken substantially in the plane of line 4- on Fig. 2. I

Referring particularly to Fig. l, the numeral It] indicates generally an oil burning furnace including a wall II formed in any suitable manner to provide a combustion chamber I2. The

wall II is provided with an opening I3 in which is secured an air cone member or nozzle I4 having a centrally disposed orifice I6 through which secondary air for supporting combustion in the combustion chamber I2 is discharged. The

member I4 also is provided with a plurality of spaced openings I 'Isurrounding the opening or orifice I6for supplying additional quantities of secondary air to the combustion chamber;-

Disposed axially with respect to the opening I6 and positioned-somewhat outside of the open- 1 ing I6, with respect to the combustion chamber i2, is a primary fuel and air mixing nozzle I8 which is secured upon the end of an air supply conduit I 9 forming a part of a casing 2| of a fueland air pumping unit of a low-pressure oil burner, not shown. The oil burner referred to also is provided with a suitable fan associated with the fuel and air pumping unit referred to, this fan being'adapted for supplying secondary air through any suitable conduit means, not shown, to the member [4 which supplies secondary air to the combustion chamber through the opening I6. For a more complete description of an oil burner system of this type and the primary and secondary air and fuel pumping, metering and fan mechanism employed therein, reference may be'had to the co-pending applications for United States Letters Patent of Howard E. Earl, Serial No. 2,881 filed January 17, 1948, for OilBurner System, now Patent No. 2,554,491, issued May 29, 1951; Howard E. Earl. Serial No. 772,970, filed September 9, 1947, for Motor Compressor Unit, now Patent No. 2,542,121; and Robert R. WitherelL' Serial No. 13,718,'filed March 8, 1948, for Oil Burner Pumping Unit. A

The nozzle I8 comprises an outer tubular body 22 provided with a knife edge orifice 23 disposed concentrically with respect to an end wall 24 "with which the tubular member 22 is provided. The orifice 23 is located just outside of the opening I6 and is adapted to discharge into the combustion chamber I2 through the center of the opening 16 a blast of primary fuel and'air formed by the nozzle I8. I

The inner surface of the end 24 of the body 22 is of 'frusto-conical formation indicated at 25, and the reduced end of this surface terminates in the knife edge orifice 23. Located within the outer tubular body'or member 22 is an inner tubular body or member 26, the front portion of which is formed to provide a tapering annular seat 21 which engages the inner tapering surfac 25 of the outer tubular member 22. The forward end of the inner tubular body 26 is of reduced cylindrical formation as is indicated at 28 to provide within the inner cylindrical surface 29 of the outer body 22 an an- .nular fuel and air mixing chamber indicated Beyond the annular seat 21, the front end portion of the inner tubular body 26 is provided with an annular surface 32 which is disposed normally with respect to the axis of the body 26 and from the central portion of which surface projects a conical tip 33. The tip projects into the orifice 23 adjacent the end of the tip concentrically with respect to the orifice.

The surface between the front end of the inner tubular body 26 and the end wall 24 of the outer tubular body 22 provides a tip chamber 34 which surrounds the tip 33 and is in open communication with the orifice 23. The tip chamber 34 is separated from the annular mixing chamber 3|- by engagement between the inner and outer bodies 26 and 22 respectively at the tapering annular seating surface 21.

However, communication between the tip chamber 34 and the annular mixing chamber 3| is provided by a plurality of annularly disposed passages or notches indicated at 36. The forward ends 31 of the notches 36 terminate upon the annular surface 32 formed on the end of the inner tubular body 26 .in tangential relation to the tip chamber 34. The rearward ends 38 of the passages 36 likewise terminate in tangential relation to the annular chamber 3| beyond the tapering annular seating surface 21. The passages 36 are located eccentrically with respect to the forward end of the inner tubular member 26 and terminate in the chambers 34 and 3| in equally spaced relation.

Rearwardly of the annular mixing chamber 3|, the inner tubular body 26 is formed to provide a plurality of longitudinally disposed channels 39, the forward ends of the channels being in open communication with the annular chamber 3| midway between the rearward ends of the passages- 36. The inner walls of the channels 39 are formed by planular surfaces which extend in opposite directions toward the inner cylindrical surface of the outer body 22 and are tangent to the exterior cylindrical surface 28 of the inner body Between the channels 39 the inner body 26 is formed to provide longitudinally disposed arouate seating surfaces 4| which engage the cylindrical inner surface 29 of the outer body 22 for the purpose of separating the channels 39. The inner body 26 is provided with a concentrically and longitudinally disposed opening 42 which is formed internally thereof, the front end of this opening being: closed by the front end of the inner body 26.

At the rearward end thereof, the opening 42 is adapted to receive a tube 43 which is supplied by oil from a conduit 44 which communicates with the oil pumping mechanism of the primary fuel and air pumping unit heretofore referred to. The tube 43 also projects within the conduit 44 and is surrounded by a coil spring 46, the opposite ends of which engage the adjacent ends of the conduit 44 and the inner tubular body 26. The coil spring 46 urges the body 26 forwardly into resilient engagement with the outer tubular body 22 at the annular seating surface 21.

The primary air supply conduit |9 surrounds the oil supply conduit 44 and the tube 43, and the annular space therebetween communicates with the rearward ends of the channels 39 for supplying primary air to the channels. The opening 42 within the body 26 also communicates with the channels 39 intermediate the opposite ends there- 'of through radially disposed openings indicated at 41.

' sages 41 flows relatively slowly into the channels over the sharp outer ends of the passages 41. The fuel from the passages 41 is picked up in atomized form by the air moving forwardly in the channels, the mixture thereby formed flowing into the annular mixing chamber 3|. The fue1 and air mixture so formed tends to rotate around the annular mixing chamber 3| at relatively lower velocity than the velocity of the mixture in the channels 39. Such rotation of the mixture in the annular mixing chamber 3| is caused by the tangential relation of the rearward ends of the passages 36 to the annular mixing chamber 3|.

However, some of the mixture rotating within the annular mixing chamber 3| is continually being discharged from the mixing chamber 3| into the tip chamber 34 through the passages 36. The passages 36 being much smaller in cross section than the annular mixing chamber 3|, it will be apparent that the velocity of the mixture in the passages 36 will be greatly increased. Such change of velocity of the mixture in flowing from the annular mixing chamber 3| into the rearward ends of the passages 36 across the sharp edges which are formed by the rearward ends of the passages 36 tends to improve the atomization of the fuel in the fluid mixture traversing the passages 36. When the mixture is discharged from the passages 36 into the tip chamber 34, the mixture continues to rotate in the tip chamber in the same direction in which the mixture rotated in the annular mixing chamber 3 I.

From the tip chamber 34 the primary mixture is discharged from the orifice 23 in a blast which flows through the orifice |6 in concentric relation thereto. As the mixture flows through the orifice 23, the fuel in the fluid mixture is further atomized by the knife edge formation of the orifice 23. Beyond the orifice 23, the primary mixture may be ignited by an electric current which jumps a gap between the forward ends of a pair of electrodes indicated at 48, and thereafter the mixture will burn beyond the opening It in the blast of secondary air which is discharged into the combustion chamber 2 by the secondary air nozzle or member |4.

When the burner is shut off by the operation of the burner control system, the fuel which collects around the orifice 23 will adhere to the tip 33 and the end of the nozzle thereby will be pre-- vented from dripping oil during the inoperative periods of the burner.

While I have illustrated and described a preferred embodiment of my invention, it is understood that this is capable of modification, and I therefore do not wish to be limited to the precise details set forth, but desire to avail myself of such changes and alterations as fall within the purview of the following claims.

I claim:

1. An oil burner nozzle comprising an outer tubular body having a circular sharp edged orifice formed coaxially therewith at the front end thereof, an inner tubular body within said outer body and having a front end formed to provide an annular seat disposed in engagement with said outer body and being spaced from said outer body on opposite sides of said seat to provide a tip chamber communicating with said orifice and an annular mixing chamber separated from said tip chamber by said seat, said front end of said inner tubular body having a conical tip projecting toward said orifice and concentrically with respect thereto, one of said bodies being formed to provide a plurality of passages across said seat between said mixing chamber and said tip chamber, said passages being formed in similarly sloped relation and being disposed in directions eccentrically of said mixing chamber and said tip chamber with the opposite ends of said passages terminating in each of said chambers in directions tangently related to said chambers so as to induce a unidirectional rotation of fluid in said mixing chamber and in said tip chamber, said inner body on the side of said annular chamber remote from said annular seat being formed t provide a plurality of plane surfaces extending toward the inner wall of said outer body, said inner body between the adjacent extremities of said plane surfaces being formed to provide seats engaging the interior of said outer body for dividing the space between said inner and outer bodies into a plurality of longitudinally disposed air supply and mixing channels communicating at their forward ends with said annular chamber and through which air supply and mixing channels air under pressure is supplied to said mixing chamber, a plurality of spaced oil supply ports extending between the interior of said inner tubular body and said air supply and mixing channels and through which oil supply ports oil under pressure is supplied to said channels, the outer ends of said ports forming relatively sharp edges across said channels facing the direction of flow of fluid in said channels toward said annular chamber, said sharp edges being positioned between the opposite ends of said channels and in advance of said passage ends in said annular chamber, said oil supply ports discharging jets of oil into said air flowing through said air supply and mixing channels, said nozzle construction being such that oil is mixed with air in said air supply and mixing channels and such mixture is rotated in said annular chamber and in flowing from said annular chamber into said passages such mixture breaks over the edges of said passages and changes directions, and such mixture further breaks over the edge of said orifice and changes direction in passing from said tip chamber through said orifice.

2. An oil burner nozzle comprising an outer tubular body having a circular sharp edged orifice formed coaxially therewith at the front end thereof, an inner tubular body within said outer body and having a front end formed to provide an annular seat disposed in engagement with said Jul outer body and being spaced from said outer body on opposite sides of said seat to provide a tip chamber communicating with said orifice and an annular mixing chamber separated from said tip chamber by said seat, said front end of said inner tubular body having a conical tip projecting toward said orifice and concentrically with respect thereto, one of said bodies being formed to provide a plurality of passages across said seat between said mixing chamber and said tip chamber, the cross section of said passages being materially less than that of said annular chamber, said passages being formed in similarly sloped relation and being disposed in directions eccentrically of said mixing chamber and said tip chamber with the opposite ends of said passages terminating in equally spaced relation within said mixing chamber and said tip chamber, said passage ends opening into each of said chambers in directions tangently related to said chambers so as to induce a unidirectional rotation of fluid in said mixin chamber and in said tip chamber, said inner body on the side of said annular chamber remote from said annular seat being formed to provide a plurality of longitudinally disposed seats engaging the interior of said outer body for dividing the space between said inner and outer bodies into a plurality of longitudinally disposed air supply and mixing channels communicating at their forward ends with said annular chamber and through which air supply and mixing channels air under pressure is supplied to said mixing chamber, a plurality of spaced oil supply ports extending between the interior of said inner tubular body and said air supply and mixing channels and through which oil supply ports oil under pressure is supplied to said channels, the outer ends of said ports formin relatively sharp edges across said channels facing the direction of flow of fluid in said channels toward said annular chamber, said sharp edges being positioned between the opposite ends of said channels and in advance of said passage ends in said annular chamber.

HOWARD E. EARL.

REFERENCES CITED The following references are of record in the file of this patent: 

